This is an application for a K24 Mid-career Investigator Award in Patient Oriented Research (POR). The applicant is Eric Strain, a physician-researcher in the Department of Psychiatry at Johns Hopkins University School of Medicine. Dr. Strain has devoted his career to POR, and specifically to issues related to research on drug abuse and to treatment of substance abusing patients. His areas of focus have included the development of medications for the treatment of opioid and cocaine dependence, the testing of medications combined with behavioral treatment interventions, the role of psychiatric symptoms and comorbidity in substance use disorders, the testing of abuse liability of medications, and the special treatment needs of women and men with substance abuse. This application describes the candidate's three immediate career goals (to recruit young physicians/clinical investigators to conduct research fellowships in clinical addictions research, to integrate these clinical investigators into ongoing and new studies of POR conducted at the BPRU by providing direct experience in all aspects of clinical investigation, and to assist and mentor these clinical investigators in the transition from fellow to junior faculty member, encouraging each to continue in a career path of addictions-related research). In addition, three long-term career goals are also described (to develop a group of junior, mid-level, and senior clinician investigators with expertise in conducting addictions-related research to serve as a next generation of investigators in substance abuse research at Johns Hopkins, to maintain current investigative strengths of the BPRU while building new complementary areas of clinical research through collaborative efforts within the research community, and to utilize this investigative team in advancing scientific understanding of addictive disorders and their treatment through coordinated efforts). These goals will be accomplished through currently funded research efforts, and a clinical pharmacology study is succinctly presented to illustrate work currently funded by the candidate. In addition, funds from the present application will be used for pilot studies to be conducted with young clinicians, and the research plan for a study comparing tramadol to buprenorphine for the treatment of opioid withdrawal is presented. This work is highly relevant to the mission of NIH and NIDA. Recruiting and training young clinical investigators in the area of addictions are needed to advance understanding and treatment of these disorders. The applicant is well positioned to recruit young clinical investigators, has experience in successfully mentoring young researchers, and is in a strong research environment with excellent resources for mentoring and providing high quality clinical research experiences.